An image sensor may measure image information of an object by converting photo-charges incident from the object (or, a target object) into an electrical signal. Images sensors may include a CMOS (Complementary metal-oxide-semiconductor) image sensor, a CCD (Charge Coupled Device) image sensor, etc.
An image sensor may measure a distance based on a time taken until a pulse-shaped light signal output from a source is reflected by a target object and is returned. A Time-Of-Flight (TOF) measurement technique may be used as a distance measurement technique of the image sensor.
A rolling shutter technique may be used as an image sensor driving technique. In the rolling shutter technique, a Correlated Double Sampling (CDS) operation may be performed by a column unit. If the CDS operation is not performed, a coupling may arise between columns. The coupling may cause the image sensor to experience a Fixed Pattern Noise (FPN) according to the coupling. This FPM may cause a system operation to be unstable.